Low noise mixer

Abstract

One embodiment relates to a mixer for providing a mixed output signal. The mixer includes a radio-frequency (RF) stage, first and second power dividers, and first and second frequency-conversion stages. The RF stage includes a first differential pair. The first power divider is coupled to a first transistor of the first differential pair, and the second power divider is coupled to a second transistor of the first differential pair. The first frequency-conversion stage, which is adapted to provide a first converted-frequency signal, includes a second differential pair coupled to the second power divider and a third differential pair coupled to the first power divider. The second frequency-conversion stage, which is adapted to provide a second converted-frequency signal, includes a fourth differential pair coupled to the second power divider and a fifth differential pair coupled to the first power divider. Other techniques are also provided.

1 - 13 . (canceled) 
     
     
         14 . A mixer for providing a mixed output signal, comprising:
 a radio-frequency (RF) stage comprising a first differential pair, wherein the first differential pair comprises a first transistor and a second transistor;   a first frequency-conversion stage adapted to provide a first converted-frequency signal, the first frequency-conversion stage comprising: a second differential pair of transistors coupled to the second transistor and a third differential pair of transistors coupled to the first transistor;   a second frequency-conversion stage adapted to provide a second converted-frequency signal, the second frequency-conversion stage comprising: a fourth differential pair of transistors coupled to the second transistor and a fifth differential pair of transistors coupled to the first transistor.   
     
     
         15 . The mixer of  claim 14 , where the first and second power dividers comprise transmission line. 
     
     
         16 . The mixer of  claim 14 , further comprising:
 a summation element adapted to sum the first converted-frequency signal with the second converted-frequency signal, thereby providing the mixed output signal.   
     
     
         17 . The mixer of  claim 16 , where the first and second transistors of the first differential pair of transistors are formed on a substrate comprising at least one of the following: a binary-compound semiconductor, a tertiary-compound semiconductor, or a higher-order compound semiconductor. 
     
     
         18 . The mixer of  claim 17 , where the summation element comprises semiconductor devices formed on a silicon substrate. 
     
     
         19 . A method of providing a mixed output signal, comprising:
 providing a radio frequency input signal exhibiting an RF frequency;   based on the radio frequency input signal, generating a first current signal from a first transistor of a differential pair of transistors and generating a second current signal from a second transistor of the differential pair of transistors;   using a first frequency conversion stage to generate a first converted-frequency signal based on the first and second current signals, wherein the first frequency converted signal includes a converted-frequency that differs from the RF frequency;   using a second frequency conversion stage to generate a second converted-frequency signal based on the first and second current signals, wherein the second frequency converted signal includes the converted-frequency that differs from the RF frequency; and   summing magnitudes of the first and second converted-frequency signals to generate a mixed output signal.   
     
     
         20 . The method of  claim 19 , where generating the first and second converted frequency signals is also based on an oscillation signal having a oscillation frequency different from the RF frequency. 
     
     
         21 . The method of  claim 20 , where the first and second converted-frequency signals each comprise:
 a first frequency component equal to a sum of the RF frequency plus the oscillation frequency; and   a second frequency component equal to a difference between the RF frequency and the oscillation frequency.   
     
     
         22 . The method of  claim 19 , where the mixed output signal has a magnitude that is greater than magnitudes of the first and second converted-frequency signals. 
     
     
         23 . (canceled)